Pavel Chromy: telnet line buffer size checking, history does not store repeating lines, improved history printing, log callback tweak

git-svn-id: svn://svn.berlios.de/openocd/trunk@491 b42882b7-edfa-0310-969c-e2dbd0fdcd60

1 files changed, 87 insertions, 67 deletions

diff --git a/src/server/telnet_server.c b/src/server/telnet_server.c
index 95fe422b..73579e4b 100644
--- a/src/server/telnet_server.c
+++ b/src/server/telnet_server.c
@@ -47,9 +47,9 @@ static char *negotiate =
 		"\xFF\xFB\x01"		/* IAC WILL Echo */
 		"\xFF\xFD\x03"		/* IAC DO Suppress Go Ahead */
 		"\xFF\xFE\x01";		/* IAC DON'T Echo */
-		
+
 #define CTRL(c) (c - '@')
-	
+
 /* The only way we can detect that the socket is closed is the first time
  * we write to it, we will fail. Subsequent write operations will
  * succeed. Shudder!
@@ -72,18 +72,18 @@ int telnet_prompt(connection_t *connection)
 {
 	telnet_connection_t *t_con = connection->priv;
 
-    telnet_write(connection, "\r", 1); /* the prompt is always placed at the line beginning */
+	telnet_write(connection, "\r", 1); /* the prompt is always placed at the line beginning */
 	return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
 }
 
 int telnet_outputline(connection_t *connection, const char *line)
 {
 	int len;
-	
+
 	/* process lines in buffer */
 	while (*line) {
 		char *line_end = strchr(line, '\n');
-		
+
 		if (line_end)
 			len = line_end-line;
 		else
@@ -100,32 +100,40 @@ int telnet_outputline(connection_t *connection, const char *line)
 			line += len;
 		}
 	}
-	
+
 	return ERROR_OK;
 }
 
 int telnet_output(struct command_context_s *cmd_ctx, char* line)
 {
 	connection_t *connection = cmd_ctx->output_handler_priv;
-	
+
 	return telnet_outputline(connection, line);
 }
 
-void telnet_log_callback(void *priv, const char *file, int line, 
+void telnet_log_callback(void *priv, const char *file, int line,
 		const char *function, const char *string)
 {
 	connection_t *connection = priv;
 	telnet_connection_t *t_con = connection->priv;
 	int i;
-	
+
+	/* if there is no prompt, simply output the message */
+	if (t_con->line_cursor < 0)
+	{
+		telnet_outputline(connection, string);
+		return;
+	}
+
 	/* clear the command line */
 	telnet_write(connection, "\r", 1);
 	for (i = strlen(t_con->prompt) + t_con->line_size; i>0; i-=16)
 		telnet_write(connection, "                ", i>16 ? 16 : i);
-
 	telnet_write(connection, "\r", 1);
+
+	/* output the message */
 	telnet_outputline(connection, string);
-	
+
 	/* put the command line to its previous state */
 	telnet_prompt(connection);
 	telnet_write(connection, t_con->line, t_con->line_size);
@@ -152,9 +160,9 @@ int telnet_new_connection(connection_t *connection)
 	telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
 	telnet_service_t *telnet_service = connection->service->priv;
 	int i;
-	
+
 	connection->priv = telnet_connection;
-	
+
 	/* initialize telnet connection information */
 	telnet_connection->closed = 0;
 	telnet_connection->line_size = 0;
@@ -162,22 +170,22 @@ int telnet_new_connection(connection_t *connection)
 	telnet_connection->option_size = 0;
 	telnet_connection->prompt = strdup("> ");
 	telnet_connection->state = TELNET_STATE_DATA;
-	
+
 	/* output goes through telnet connection */
 	command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
-	
+
 	/* negotiate telnet options */
 	telnet_write(connection, negotiate, strlen(negotiate));
-	
+
 	/* print connection banner */
 	if (telnet_service->banner)
 	{
 		telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
 		telnet_write(connection, "\r\n\0", 3);
 	}
-	
+
 	telnet_prompt(connection);
-	
+
 	/* initialize history */
 	for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 	{
@@ -187,11 +195,11 @@ int telnet_new_connection(connection_t *connection)
 	telnet_connection->current_history = 0;
 
 	target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
-	
+
 	log_add_callback(telnet_log_callback, connection);
 
 
-	
+
 	return ERROR_OK;
 }
 
@@ -219,9 +227,9 @@ int telnet_input(connection_t *connection)
 	char *buf_p;
 	telnet_connection_t *t_con = connection->priv;
 	command_context_t *command_context = connection->cmd_ctx;
-	
+
 	bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
-	
+
 	if (bytes_read == 0)
 		return ERROR_SERVER_REMOTE_CLOSED;
 	else if (bytes_read == -1)
@@ -229,7 +237,7 @@ int telnet_input(connection_t *connection)
 		ERROR("error during read: %s", strerror(errno));
 		return ERROR_SERVER_REMOTE_CLOSED;
 	}
-	
+
 	buf_p = buffer;
 	while (bytes_read)
 	{
@@ -244,9 +252,15 @@ int telnet_input(connection_t *connection)
 				{
 					if (isprint(*buf_p)) /* printable character */
 					{
-						telnet_write(connection, buf_p, 1);
-						if (t_con->line_cursor == t_con->line_size)
+						/* watch buffer size leaving one spare character for string null termination */
+						if (t_con->line_size == TELNET_LINE_MAX_SIZE-1)
+						{
+							/* output audible bell if buffer is full */
+							telnet_write(connection, "\x07", 1); /* "\a" does not work, at least on windows */
+						}
+						else if (t_con->line_cursor == t_con->line_size)
 						{
+							telnet_write(connection, buf_p, 1);
 							t_con->line[t_con->line_size++] = *buf_p;
 							t_con->line_cursor++;
 						}
@@ -254,9 +268,10 @@ int telnet_input(connection_t *connection)
 						{
 							int i;
 							memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
-							t_con->line[t_con->line_cursor++] = *buf_p;
+							t_con->line[t_con->line_cursor] = *buf_p;
 							t_con->line_size++;
 							telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
+							t_con->line_cursor++;
 							for (i = t_con->line_cursor; i < t_con->line_size; i++)
 							{
 								telnet_write(connection, "\b", 1);
@@ -273,30 +288,32 @@ int telnet_input(connection_t *connection)
 						else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
 						{
 							int retval;
-							
-							/* skip over combinations with CR/LF + NUL */
-							if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
+
+							/* skip over combinations with CR/LF and NUL characters */
+							if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)))
 							{
 								buf_p++;
 								bytes_read--;
 							}
-							if ((*(buf_p + 1) == 0) && (bytes_read > 1))
+							if ((bytes_read > 1) && (*(buf_p + 1) == 0))
 							{
 								buf_p++;
 								bytes_read--;
 							}
 							t_con->line[t_con->line_size] = 0;
-							
+
 							telnet_write(connection, "\r\n\x00", 3);
-							
+
 							if (strcmp(t_con->line, "history") == 0)
 							{
 								int i;
-								for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
+								for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++)
 								{
-									if (t_con->history[i])
+									/* the t_con->next_history line contains empty string (unless NULL), thus it is not printed */
+									char *history_line = t_con->history[(t_con->next_history + i) % TELNET_LINE_HISTORY_SIZE];
+									if (history_line)
 									{
-										telnet_write(connection, t_con->history[i], strlen(t_con->history[i]));
+										telnet_write(connection, history_line, strlen(history_line));
 										telnet_write(connection, "\r\n\x00", 3);
 									}
 								}
@@ -304,43 +321,46 @@ int telnet_input(connection_t *connection)
 								t_con->line_cursor = 0;
 								continue;
 							}
-							
-							/* Save only non-blank lines in the history */
-							if (t_con->line_size > 0)
+
+							/* save only non-blank not repeating lines in the history */
+							char *prev_line = t_con->history[(t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
+							if (*t_con->line && (prev_line == NULL || strcmp(t_con->line, prev_line)))
 							{
 								/* if the history slot is already taken, free it */
 								if (t_con->history[t_con->next_history])
 								{
 									free(t_con->history[t_con->next_history]);
 								}
-		
+
 								/* add line to history */
 								t_con->history[t_con->next_history] = strdup(t_con->line);
 
 								/* wrap history at TELNET_LINE_HISTORY_SIZE */
 								t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
-							
+
 								/* current history line starts at the new entry */
 								t_con->current_history = t_con->next_history;
-							
+
 								if (t_con->history[t_con->current_history])
 								{
 									free(t_con->history[t_con->current_history]);
 								}
 								t_con->history[t_con->current_history] = strdup("");
 							}
-							
+
 							t_con->line_size = 0;
-							t_con->line_cursor = 0;
 
+							t_con->line_cursor = -1; /* to supress prompt in log callback during command execution */
 							retval = command_run_line(command_context, t_con->line);
+							t_con->line_cursor = 0;
+
 							if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 								return ERROR_SERVER_REMOTE_CLOSED;
 
 							retval = telnet_prompt(connection);
 							if (retval == ERROR_SERVER_REMOTE_CLOSED)
 								return ERROR_SERVER_REMOTE_CLOSED;
-							
+
 						}
 						else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
 						{
@@ -353,7 +373,7 @@ int telnet_input(connection_t *connection)
 									t_con->line_cursor--;
 									t_con->line_size--;
 									memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
-									
+
 									telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 									telnet_write(connection, " \b", 2);
 									for (i = t_con->line_cursor; i < t_con->line_size; i++)
@@ -453,7 +473,7 @@ int telnet_input(connection_t *connection)
 							telnet_clear_line(connection, t_con);
 							t_con->line_size = strlen(t_con->history[last_history]);
 							t_con->line_cursor = t_con->line_size;
-							memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
+							memcpy(t_con->line, t_con->history[last_history], t_con->line_size);
 							telnet_write(connection, t_con->line, t_con->line_size);
 							t_con->current_history = last_history;
 						}
@@ -467,7 +487,7 @@ int telnet_input(connection_t *connection)
 							telnet_clear_line(connection, t_con);
 							t_con->line_size = strlen(t_con->history[next_history]);
 							t_con->line_cursor = t_con->line_size;
-							memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
+							memcpy(t_con->line, t_con->history[next_history], t_con->line_size);
 							telnet_write(connection, t_con->line, t_con->line_size);
 							t_con->current_history = next_history;
 						}
@@ -493,19 +513,19 @@ int telnet_input(connection_t *connection)
 							t_con->line_size--;
 							/* remove char from line buffer */
 							memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
-							
+
 							/* print remainder of buffer */
 							telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 							/* overwrite last char with whitespace */
 							telnet_write(connection, " \b", 2);
-							
+
 							/* move back to cursor position*/
 							for (i = t_con->line_cursor; i < t_con->line_size; i++)
 							{
 								telnet_write(connection, "\b", 1);
 							}
 						}
-							
+
 						t_con->state = TELNET_STATE_DATA;
 					}
 					else
@@ -529,7 +549,7 @@ int telnet_input(connection_t *connection)
 					ERROR("BUG: unexpected value in t_con->last_escape");
 					t_con->state = TELNET_STATE_DATA;
 				}
-				
+
 				break;
 			default:
 				ERROR("unknown telnet state");
@@ -539,7 +559,7 @@ int telnet_input(connection_t *connection)
 		bytes_read--;
 		buf_p++;
 	}
-	
+
 	return ERROR_OK;
 }
 
@@ -547,15 +567,15 @@ int telnet_connection_closed(connection_t *connection)
 {
 	telnet_connection_t *t_con = connection->priv;
 	int i;
-	
+
 	log_remove_callback(telnet_log_callback, connection);
-	
+
 	if (t_con->prompt)
 	{
 		free(t_con->prompt);
 		t_con->prompt = NULL;
 	}
-	
+
 	for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 	{
 		if (t_con->history[i])
@@ -564,10 +584,10 @@ int telnet_connection_closed(connection_t *connection)
 			t_con->history[i] = NULL;
 		}
 	}
-	
+
 	/* if this connection registered a debug-message receiver delete it */
 	delete_debug_msg_receiver(connection->cmd_ctx, NULL);
-	
+
 	if (connection->priv)
 	{
 		free(connection->priv);
@@ -577,7 +597,7 @@ int telnet_connection_closed(connection_t *connection)
 	{
 		ERROR("BUG: connection->priv == NULL");
 	}
-	
+
 	target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 
 	return ERROR_OK;
@@ -588,27 +608,27 @@ int telnet_set_prompt(connection_t *connection, char *prompt)
 	telnet_connection_t *t_con = connection->priv;
 
 	if (t_con->prompt != NULL)
-	    free(t_con->prompt);
-	
+		free(t_con->prompt);
+
 	t_con->prompt = strdup(prompt);
-	
+
 	return ERROR_OK;
 }
 
 int telnet_init(char *banner)
 {
 	telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
-	
+
 	if (telnet_port == 0)
 	{
 		WARNING("no telnet port specified, using default port 4444");
 		telnet_port = 4444;
 	}
-	
+
 	telnet_service->banner = banner;
-	
+
 	add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
-	
+
 	return ERROR_OK;
 }
 
@@ -616,10 +636,10 @@ int telnet_register_commands(command_context_t *command_context)
 {
 	register_command(command_context, NULL, "exit", handle_exit_command,
 					 COMMAND_EXEC, "exit telnet session");
-	
+
 	register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
 					 COMMAND_CONFIG, "");
-	
+
 	return ERROR_OK;
 }